1. Field of the Invention
This invention relates to human nail coatings and methods for coating keratinous surfaces. More particularly, the invention relates to strippable water based fingernail coating systems.
2. Description of the Prior Art
Coatings for cosmetic purposes also known as nail polishes or nail enamels have been used for many years to provide lustrous, smooth and clear or pigmented finishes to human fingernails. It is preferable that these coatings be easily applied, have a high lustre upon drying, dry rapidly and be substantially non-toxic. Removal of nail enamels is usually messy and time consuming. Thus, it is desirable that such coatings be reasonably durable to avoid the necessity of reapplication at frequent intervals.
Nail polishes as well as base coat and top coat systems currently in use include nitrocellulose in flammable organic solvents. These polishes have an unpleasant odor and are toxic. Such polishes adhere firmly to the fingernail. Removal is commonly facilitated by organic solvents which soften and dissolve the coating. The worn or softened coatings along with the removal solvents must still be wiped or rubbed off the nail. The polish removers also have unpleasant, penetrating odors, are toxic and flammable. In addition, the use of such compositions may cause damage to the nail and cuticle. Organic solvents tend to defat and thereby dry the nails which may then become brittle and unsightly. Nail polishes are commonly sold in glass containers as they have a tendency to react with many types of plastics. Because of shipping weight and marketability, it would be desirable to package nail polishes in clear plastic containers.
Efforts to mitigate some of these problems have been described such as by precoating the nail with a base comprising a film forming resin compound which includes a vinyl chloride-vinyl acetate copolymer as described in U.S. Pat. No. 2,764,168, issued Sept. 25, 1956 to Benno Herz. After the nail is precoated with such a solution and allowed to set, an ordinary nitrocellulose lacquer based fingernail polish is applied. The nail polish is said to be removable from the base without use of solvents, however, such compositions require an inconvenient and time consuming two-step process.
Another multicoat process and composition is described in U.S. Pat. No. 3,928,113, Rosenberg, issued Dec. 23, 1975 in which a base coat of a composition comprising a water soluble or water swellable polymer dissolved in a solvent is first applied to the nail and is allowed to dry. Thereafter, a photocurable polymer composition is applied to the precoated nail and is then exposed to a light source to set the photocurable polymer. This process is time consuming, requiring exposure to light for curing as well as two distinct applications. Removal requires soaking in water followed by wiping or rubbing off the worn polish.